ecr959 - I don't want to bust your bubble or harp on this anymore, but that chain can be cut with bolt cutters in 5 seconds and will only deter someone without bolt cutters (which is most people I would agree).
If you want to rely on that lock and chain when the bike is parked in a well-trafficked public space in the daytime, it's probably OK, but then you wouldn't need it anyway. If you think that will make a big difference if parked outside on a dimly lit quiet street, probably not.
All you are doing with any of these things is really making your bike a little less attractive and only a tiny bit more difficult to steal. It may make you feel better to use that, but like I said, If someone really wants your bike, it's theirs.
Seriously, check out this reference article and video from webbikeworld.com ---
http://www.webbikeworld.com/motorcycle-alarms/